Scientists have recorded several powerful solar flares this week, one of which was the strongest in more than a decade. On Wednesday (Sept 6), the National Oceanic and Atmospheric Administration’s Space Weather Prediction Center (SWPC) said an X-class solar flare –the most powerful sun-storm category—blasted from a large sunspot on the sun’s surface at 5:10 a.m. EDT.

While that blast was the strongest reported since 2015, at X2.2, three hours later, at 8:02 a.m. EDT, a second X9.3 flare exploded from the sunspot, marking the strongest flare recorded since 2006.

An X9.3 class solar flare in the middle of the Sun on Sept. 6, 2017. Image Credit: NASA / GSFC / SDO
An X9.3 class solar flare in the middle of the Sun on Sept. 6, 2017. Image Credit: NASA / GSFC / SDO

This morning the sun blasted two more flares; the first occurring at 6:15 a.m. EDT –which was classified as an M7.3, a mid-level flare, and the second happening at 10:36 a.m. EDT. The second flare was more powerful, identified as an X1.3. X-class solar flares are the most powerful.

Solar flares caused radio blackouts throughout the world

Solar flares are bright flashes of radiation are emitted from magnetically active regions on the surface of the sun. When the magnetic fields from the sun become entangled and twisted, they send giant bursts of energy speeding toward our planet in a matter of minutes.

Moreover, particularly intense magnetic storms on the sun’s surface can send massive clouds of plasma known as coronal mass ejections (CMEs), which can take up to three days to reach Earth.

Astronomers at NASA’s Solar Heliospheric Observatory detected a CME emerging from one of two massive sunspots on the sun’s surface, called active region 2673, after the two blasts on Wednesday. However, they haven’t determined whether the CME will hit our planet directly.

“It was accompanied by radio emissions that suggest there’s a potential for a CME,” SWPC space scientist Rob Steenburgh told “However, we have to wait until we get some coronagraph imagery that would capture that event for a definitive answer.”

But another CME that emerged from the sunspot on Monday (Sept 4) made its way to Earth in two days, according to the SWPC. Scientists predicted that CME would supercharge auroras Wednesday night, although the aurora forecast looks unaltered for the coming days.

The latest solar flares have resulted in radio blackouts, as high-frequency radio experienced a “wide area of blackouts, loss of contact for up to an hour over [the] sunlit side of Earth,” and low-frequency communication, used for navigation, was degraded for an hour, according to a Wednesday statement by the SWPC.

Powerful solar flares come during the sun’s solar minimum

The sunspot responsible for the four solar flares this week, active region 2673, is the smaller one of two massive spots on the sun’s surface, measuring seven Earths wide by nine Earths tall, according to astrophysicist Karl Battams.

On Tuesday (Sept 5) that sunspot blasted an M-class solar flare –midlevel, about one-tenth the size of an X-class flare—which led to a coronal mass ejection aimed toward our planet that astronomers said it could cause auroras Wednesday night as far south as Ohio and Indiana.

If CMEs from the latest flares are aimed toward Earth, they could cause more spectacular auroras, as well as damages to satellites, communications, and power systems. That CME could arrive within 1 to 3 or 4 days, according to Steenburgh, although clouds of charged plasma triggered by energetic flares usually arrive quickly.

An Earth aurora seen from the ISS. Image Credit: ESA
An Earth aurora seen from the ISS. Image Credit: ESA

Astronomers are puzzled by the latest surge of solar activity, as the sun is approaching its solar minimum, with the lowest level of activity in its 11-year cycle.

“We are heading toward solar minimum, but the interesting thing about that is you can still have events, they’re just not as frequent,” Steenburgh told “We’re not having X-flares every day for a week, for instance – the activity is less frequent, but no less potentially strong. These kind of events are just part of living with a star.”

Auroras will be seen as far as Chicago and Seattle

Today, the SWPC issued a new G3 geomagnetic storm watch, “in anticipation of the arrival of another CME associated with the X9.3 flare” that occurred on Wednesday. The watch will remain in effect until Saturday.

NOAA’s space weather site predicts a potential aurora visible in places like Seattle and Chicago over the weekend as a result of the solar storm. Apart from the amazing auroras, the geomagnetic storm could disrupt satellite communications.

Particularly intense geomagnetic storms can cause massive power outages and damages to electrical systems. In fact, particles from a solar storm once interfered with a voting machine in a 2003 Belgian election, swapping at least 4096 votes, as reported by Gizmodo.